Although a considerable body of research has documented the association between victimization experience and adolescent mental health, previous studies have not investigated the mediating effects of personality characteristics such as social competence and self-mastery on the associations between cyberbullying victimization and mental health. This study aims to fill in this research gap. Random group sampling based on grade was employed, and a total of 607 adolescents (51.07% females, M[subscript age] = 15.04) were recruited to participate in the study. The findings of the present study partially supported the hypotheses. Specifically, the results showed that cyberbullying victimization was positively associated with social anxiety and depression. Self-mastery was found to mediate the relationship between cyberbullying victimization and symptoms of depression and social anxiety. Social competence was found to be negatively related to social anxiety, but no mediating effect was found between cyberbullying victimization and symptoms of mental health. Theoretical and practical implications were discussed.